Solara and Los Vecinos are affordable housing projects that were designed with the goal of net zero energy performance with a very small increase in the incremental cost per unit. The projects also have a number of other “green” features.
More information on Solara and a link to a case study is on the Global Green website here. Information on Los Vecinos and a link to a case study is here.
Weather extremes are damaging parts of the U.S. infrastructure [NY Times]
The United States ranks 9th out of 12 of the world’s largest economies on energy efficiency but feels the least guilty [BuildingGreen.com]
Demolition began at the West Branch of the Berkeley Public Library – when completed, it will be a zero net energy building [Berkeleyside]
The Feds say the PACE retrofit program is still too risky [BuildingGreen.com]
Photo: A blooming artichoke in Berkeley, CA, by Anna LaRue
One of the first panel sessions I went to featured a talk by Jeff Harris, of the Alliance to Save Energy.
He covered a lot of ground in defining “net-zero energy,” covering state and federal goals around NZE, detailing many of the appeals of NZE, and then focusing on the potential of NZE communities.
What I found most interesting during his talk was the specific examples of the military’s focus on getting a number of bases to NZE. He noted that there are more than 6 pilot sites targeting ZNE (often used interchangeably with NZE) by 2020. Two of the sites have the additional aggressive goal of being “triple-net-zero,” or net zero energy, water, and waste.
He also mentioned a specific site – Fort Carson – and showed some analysis (I think by the National Renewable Energy Lab, NREL) of what kinds of strategies and systems will be needed to achieve the ZNE goal.
After the session, I found an NREL report online that provides significant detail on the recommendations provided for Fort Carson” “Targeting Net Zero Energy at Fort Carson: Assessment and Recommendations” (link opens a PDF).
photo attribution: CalderOliver at en.wikipedia
Zero Net Energy (ZNE) is a term that is increasingly heard throughout the architecture and building sector, but it is also a term that can mean different things to the different people who use it. This series of posts is an overview of the four common definitions of ZNE, and a brief expansion on their respective implications in relation to policy structures and physical infrastructure. Part 1 of the post can be found here
The four common definitions of ZNE are: 1. Zero Net Site Energy, 2. Zero Net Source Energy, 3. Zero Net Energy Cost, and 4. Zero Net Energy Emissions. All four of these calculations are as measured over a calendar year, or on an annual basis. The difference is in the metric (the “thing” being measured) and the boundary (what is included in the calculation). All four definitions can be applied to –and calculated at– a “community” or multiple-building scale as well. In all cases the “net” part refers to how energy is accounted for at the grid level; low energy buildings that are not grid tied would therefore not be under a zero net energy designation.
Part 2: Zero Net Source Energy
what this is: A source zero net energy building produces at least as much energy as it uses in a year when accounted for at the source.
what this means: “Source energy” refers to both the energy used by the building and the energy lost in the generation and delivery of the energy to the building. To illustrate the point, think of carrying a bucket of water with a small leak across a room; you then water a plant with it. The ZNE site definition would only be concerned with the water that was applied to the plant; the ZNE source definition would be concerned with both the water that was applied to the plant, and the water that leaked out onto the floor.
pros, cons & considerations:
further reading:
P. Torcellini et al., Zero Energy Buildings: A Critical Look at the Definition, National Renewable Energy Lab, 2006.
The International Living Future Institute (ILFI), owner of the Living Building Challenge, is going where no certification program has gone before with a new Net Zero Energy Building Certification program (BuildingGreen.com). 
You can read the International Living Future Institute press release on the NZE Building Certification program here. There is a zero net energy gas station in Beaverton, Oregon (OregonLive.com). KB Home, one of the largest homebuilders in the U.S., has developed ZeroHouse 2.0, a house designed to achieve net-zero energy. The home is currently available in Tampa, Florida, and in San Antonio and Austin, Texas, but the company plans to expand the availability of net-zero options to other cities throughout 2012 (BuildingGreen.com).
photo credit: Alan WalkerZero Net Energy (ZNE) is a term that is increasingly heard throughout the architecture and building sector, but it is also a term that can mean different things to the different people who use it. In this series of posts I will give an overview of the four common definitions of ZNE, and a brief expansion on their respective implications in relation to policy structures and physical infrastructure.
The four common definitions of ZNE are: 1. Zero Net Site Energy, 2. Zero Net Source Energy, 3. Zero Net Energy Cost, and 4. Zero Net Energy Emissions. All four of these calculations are as measured over a calendar year, or on an annual basis. The difference is in the metric (the “thing” being measured) and the boundary (what is included in the calculation). All four definitions can be applied to –and calculated at– a “community” or multiple-building scale as well. In all cases the “net” part refers to how energy is accounted for at the grid level; low energy buildings that are not grid tied would therefore not be under a zero net energy designation.
Part 1. Zero Net Site Energy
what this is: A Zero Net Energy Building is one that uses no more energy than it can produce on-site within one calendar year (this is the most commonly used definition of the term “zero net energy” at present).
what this means: A “site” can be defined as either the building footprint itself or the building and the property it sits on. In this definition, the building/ building site would incorporate a form of on-site renewable energy such as solar (most common), wind, small hydro or biogas. As mentioned, a ZNE building is still tied to the larger energy grid. For example, a ZNE building that generates energy through the use of solar panels would create a surplus of power while the sun was shining (and the excess power would be fed back into the grid), but would have to draw power from the grid in the evening or during cloudy days. The goal here is for the overall power drawn within one calendar year to be less than or equal to the power generated.
pros, cons & considerations: The chief benefit of this definition is that it promotes deep efficiency at the single building scale. This is because in order to viably (and cost effectively) achieve this definition of ZNE, it is much more desirable to build the lowest energy-use building possible and then add a source or renewable generation. In addition, ZNE sets a concrete goal to achieve and thus can be a more useful target than trying to meet or best shifting baselines as building performance codes change.
However, buildings are built in many types and have many necessary functions- not all of which are compatible with the site definition of ZNE. For example, hospitals, restaurants, industrial activities, etc., may all have a very hard time achieving a ZNE facility because of unusually high energy demands. In addition, high-rise buildings and urban infill sites have their own challenges due to physical constraints (poor solar access, low rooftop-to-building ratio, proximity and density issues, etc.)
The implication here is that if a ZNE site-definition goal is in place on a policy level, at a certain point it becomes necessary to start looking at the issue from a multiple-building, or “community”scale, that would allow energy balancing between buildings to achieve an overall ZNE outcome (this is a simplification, but that is the main point).
Further reading:
P. Torcellini et al., Zero Energy Buildings: A Critical Look at the Definition, National Renewable Energy Lab, 2006.
The University of California–Davis has opened its West Village development, which aims to be the largest net-zero-energy community in the country (via BuildingGreen.com). The bankruptcies of three American solar power companies in the last month, including Solyndra of California… have left China’s industry with a dominant sales position — almost three-fifths of the world’s production capacity — and rapidly declining costs (via NY Times). China was the United States’ number one source of and destination for PV products in 2010. The U.S. imported approximately $1.4 billion worth of PV products from China, while exporting between $1.7 billion and $2.0 billion. This resulted in a positive trade balance with China with net exports of $247 million to $540 million (via Greentech Media).
Many of you may have heard of ZETA Communities, a company that builds high performance and net zero energy modular housing, schools, and commercial structures that can be installed quickly and in dense urban areas.
A few weeks ago, they posted a video of how the structures are assembled in their factory,and they highlight some of the potential benefits of modular construction.
If you do not see the video embedded above, click here to watch it on YouTube.
I am also posting a video of one of their structures being installed on a site. (Note: the video does not have any sound.)
If you do not see the video embedded above, click here to watch it on YouTube.
On Tuesday, January 25, I was in the audience at the SPUR Urban Center in San Francisco as Panama Bartholomy, CEC, and Emma Wendt, PG&E, gave presentation about California’s clean energy future.
The post below consists of Part 2 of my record of the presentation – the second part of Panama Bartholomy’s presentation. All portions are included in chronological order.
An ellipsis (…) indicates that I was not able to capture the words or thoughts skipped. The presentation is transcribed as accurately as possible – punctuation choices are mine. I also added any photos or images.
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Panama Bartholomy
… …
That’s the context. Let’s get into solutions. On is zero net energy new buildings…. All new homes will produce as much energy as they use by 2020. But our challenge isn’t really new buildings. Our challenge is existing buildings… … We have 3/4 of the units in California built before there were energy codes. So that’s a real challenge….
So we adopted a very ambitious plan in California… the Long Term Energy Efficiency Strategic Plan… [highlighting retrofit goals] If you look just at the building sector and where the GHG emissions are coming from… Lighting represents 12% of all the emissions from the building sector. All the pieces get more and more efficient… Except for the “misc” category… which is basically plug loads… Flat screen TVs are 10% of residential energy consumption… and 1% of California’s total electricity consumption…. So we created standards… We had a choice of either building power plants to power all those TVs, or making efficient TVs… we chose efficient TVs.
… …
The CEC now has the authority to enforce energy reduction in existing buildings… We’re going to start by eventually requiring labeling of buildings… Eventually requiring upgrades at different parts in the lifecycle of buildings to improve energy efficiency… Please join us at the rulemaking.
But there are major market barriers… awareness… lack of coordination among the various programs… lack of a trained home performance workforce… lack of home energy rating system. And lastly, a significant lack of access to capital… One of the ways we’re addressing this is with a new program… Energy Upgrade California.
Now I want to talk about renewables… It’s a law that by the end of 2010, all IOUs need to provide at least 20% of their electricity to consumers through renewables… The IOUs have enough renewables under contract to get to 33% by 2020… … There has been intense growth in the Renewable Portfolio Standard capacity over the last few years…. …
Geothermal right now is the number 1 producer, then wind, then a significant amount of small hydro … You can get the most updated numbers on the CEC website….
There are a huge number of renewable projects going through permitting at the state and local level right now… Almost 51 MW total. Obviously, not all will get through permitting, and not all will get built, but that’s a significant number.
… …
One of the reasons the CEC was created is because we were having trouble getting new power plants built in California in the 1970s… thermal plants. We don’t do solar and we don’t do wind… The average solar project site is over 125 times larger than the average natural gas plant. So there are some major issues there… And the Mojave Desert is not a wasteland – it is a fragile ecosystem.
(Image credit: Wikimedia Commons)
Is solar a renewable resource if it destroys a fragile ecosystem that can never be replaced? … We’re seeing a need to reassess what we mean by renewable energy in California. So we’re developing the Desert Renewable Energy Conservation Plan… Starting to created a program for the future of responsible renewable energy in the Mojave Desert. … Achieving all cost-effective energy efficiency reduces the renewable energy needed to meet electricity demand… this means we can have much more strategic placement of the projects…
It comes down to a choice. California’s residents, who live mostly in cities, can put down new power plants on tortoises, or they can change some light bulbs …
… … [looking at a map of where the good wind, solar sites are] So either we need major power lines from spots in the desert to where the people are, or we need to put some PVs on a roof… or on a parking lot… …
With electricity you have a lot of options… With natural gas, you don’t have a lot of options. One is solar thermal… And we better do it quick… … Right now in China, you can buy a system for about $200. The alternative is to heat water with electricity for about $150 per year. In the US a system costs about $7500…
In California, about 42% of union trade members are on the bench right now… [looking at a chart] For every MW of construction, we can look at how many jobs are created for different generation technologies… You can invest in renewable, which are a little more expensive up front, but create jobs…and it’s pretty much free after that except for some maintenance…
Now, to summarize Brown’s plan:
We’re not going to achieve these goals in Sacramento… Politicians don’t retrofit homes… … The only way we achieve any of these goals is through leaders in community, leaders in industry, and the leaders in this room. Thank you very much for your time.
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Part 1 is posted here. Part 3 will be posted soon.
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Zero Resource 
